Search Results - "Alonso,G."

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Publication Catalog - "Alonso,G."

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  1. 1

    Caracterização da demanda de pacientes com carcinoma de colo uterino no Hospital das Clínicas da Universidade Federal de Uberlândia, Minas Gerais, Brasil, 1984-1988

    Publication
    by Pioli,Eliane Regina
    Other Authors: Oliveira,Neide M. de; Rezende,Alonso G. de
    Origin: Oasisbr
    Foi realizado um estudo retrospectivo de 180 casos de carcinoma de colo uterino internados no Hospital das Clínicas da Universidade Federal de Uberlândia, no período de 1984 a 1988, segundo variáveis pessoais e de tempo. Encontrou-se um aumento gradativo com o tempo e uma maior freqüência entre 35 e 60 anos de idade. Aproximadamente 51% das pacientes eram provenientes de outras cidades e estados. Verificou-se uma maior freqüência em multíparas e em mulheres que iniciaram sua vida sexual antes dos 20 anos. Grande parte das mulheres (45%) ainda não tinha tido a menopausa. As manifestações clínicas mais freqüentes foram sangramento genital irregular e dor em baixo ventre. A citopatologia evidenciou Papanicolaou de graus III em 60,5% dos casos. A proporção de carcinoma in situ (20,6%) foi pequena em relação aos estágios mais avançados IIb (31,6%), Ib (14,5%), e IIIa, IIIb e IV (18,9%), os quais, havendo uma orientação mais sistematizada de prevenção, podem ser encontrados com menor freqüência. A relação carcinoma invasor/carcinoma in situ foi de 2,52 no período de 1984 a 1986, aumentando para 4,75 entre 1987 e 1988, o que indica não terem sido atingidos níveis satisfatórios de prevenção da doença na cidade e na região no período estudado.
    1993 article Brazil open access
  2. 2

    Variscan intracrustal recycling by melting of Carboniferous arc-like igneous protoliths (Évora Massif, Iberian Variscan belt)

    Publication
    by Rodriguez, C.
    Other Authors: Pereira, M.F.; Castro, A.; Gutierrez-Alonso, G.; Fernandez, C.
    Bulk rock geochemistry and sensitive high-resolution ion microprobe zircon geochronology of igneous and metaigneous rocks of the Évora gneiss dome, located to the north of the reworked Rheic Ocean suture zone in the southwest Iberian Variscan belt, reveal a succession of magmatic and melting events lasting ∼30 m.y. between ca. 341–314 Ma. The study of detailed feld relationships of orthomigmatites (i.e., migmatites from igneous protoliths) and host granitic rocks proved to be crucial to reconstruct the complex sequence of tectono-thermal events of the Évora gneiss dome. The older igneous protoliths, with marked geochemical arc-like signatures, are represented by 338 ± 3 Ma tonalites and 336 ± 3 Ma diorites. These tonalites and diorites appear as mesosomes of igneous orthomigmatites containing new melts (leucosomes) of monzogranite composition and silica-poor trondhjemites formed in a melting episode at 329 ± 4/6 to 327 ± 3 Ma. The absence of peritectic phases (e.g., pyroxene), together with shearing associated with migmatization, imply the existence of water-rich fluids during melting of the older igneous rocks of the Évora gneiss dome. This melting event is coeval with the second magmatic event of the Évora gneiss dome represented by the neighboring Pavia pluton. A porphyritic monzogranite dated at 314 ± 4 Ma defnes a later magmatic event. The porphyritic monzogranite encloses large blocks of the orthomigmatites and contains magmatic mafc enclaves (autoliths) dated at 337 ± 4 Ma that are ∼23 m.y. older than the host rock. All studied rocks of the Évora gneiss dome show arc-like, calc-alkaline geochemical signatures. Our results support recycling of intermediate-mafc plutonic rocks, representing the root of an early magmatic arc that formed at the time of GondwanaLaurussia convergence (after the closure of the Rheic Ocean) and coeval subduction of the Paleotethys. A geodynamic model involving ridge subduction is proposed to explain the Early Carboniferous intra-orogenic crustal extension, dome formation, exhumation of high-grade rocks, compositional variations of magmatism and formation of new granitic magmatism in which, arc-like signatures were inherited from the crustal source.
    2022 article Portugal open access
  3. 3

    Comparison of relative renal function measured with either 99mTc-DTPA or 99mTc-EC dynamic scintigraphies with that measured with 99mTc-DMSA static scintigraphy

    Publication
    by Domingues,F. C.
    Other Authors: Fujikawa,G. Y.; Decker,H.; Alonso,G.; Pereira,J. C.; Duarte,P. S.
    Origin: Oasisbr
    OBJECTIVE: The aim of this study was to compare the renal function measured with either 99mTc-DTPA or 99mTc-EC dynamic scintigraphies with that measured using 99mTc-DMSA static scintigraphy. METHODS: the values of relative renal function measured in 111 renal dynamic scintigraphies performed either with 99mTc-DTPA (55 studies) or with 99mTc-EC (56 studies) were compared with the relative function measured using 99mTc-DMSA static scintigraphy performed within a 1-month period. The comparisons were performed using Wilcoxon signed rank test. The number of 99mTc-DTPA and 99mTc-EC studies that presented relative renal function different by more than 5% from that measured with 99mTc-DMSA, using chi square test were also compared. RESULTS: the relative renal function measured with 99mTc-EC is not statistically different from that measured with 99mTc-DMSA (p = 0.97). The relative renal function measured with 99mTc-DTPA was statistically different from that measured using 99mTc-DMSA, but with a borderline statistical significance (p = 0.05). The number of studies with relative renal function different by more than 5% from that measured with 99mTc-DMSA is higher for the 99mTc-DTPA scintigraphy (p = 0.04) than for 99mTc-EC. CONCLUSION: the relative renal function measured with 99mTc-EC dynamic scintigraphy is comparable with that measured with 99mTc-DMSA static scintigraphy, while the relative renal function measured with 99mTc-DTPA dynamic scintigraphy presents a significant statistical difference from that measured with 99mTc-DMSA static scintigraphy.
    2006 article Brazil open access
  4. 4

    The unique Cambro-Ordovician silicic large igneous province of NW Gondwana: Catastrophic melting of a thinned crust

    Publication
    by Rodriguez, C.
    Other Authors: Castro, A.; Gomez-Frutos, D.; Gutierrez-Alonso, G.; Pereira, M.F.; Fernandez, C.
    Cambro–Ordovician silicic magmatism in the Central Iberian Zone of the Iberian Massif (Ollo de Sapo Formation, OSF) constitutes a voluminous and geochemically atypical magmatic event that formed preceding the breakup of the northern margin of Gondwana. To date, and due to uncommon geochemical signatures, such as a high Fe, Mg content compared to anatectic melts and the departing from the calc-alkaline trends, the origin of such magmatic event is not fully understood. Herein, we report a data-analysis of geochemistry linking magmas and source compositions. The analysis of the combined data from multiple studies ascribes the geochemistry of the OSF rocks to a combination of extensive melting of Ediacaran metasiliciclastic rocks and a Ca-rich component. It is hypothesized that fluids released by crystallization of mafic magmas contributed to partial melting of a thick metasedimentary pile represented by Ediacaran siliciclastic rocks. Such melting event gave rise to a mobile nebulite or migma, which was able to extrude and form the super-eruption or ‘‘flare-up” that characterizes Cambro-Ordovician silicic magmatism at the Gondwana margin. Fast, catastrophic crustal melting with large-scale restite entrainment, triggered by the influx of mafic magma-derived fluids, are considered the main cause of the unique features of this Cambro-Ordovician atypical silicic large igneous province of Gondwana.
    2022 article Portugal open access
  5. 5

    Use of single photon emission computed tomography and magnetic resonance to evaluate central nervous system involvement in patients with juvenile systemic lupus erythematosus

    Publication
    by Prismich,G.
    Other Authors: Hilário,M.O.E.; Len,C.A.; Terreri,M.T.; Quaresma,M.R.; Alonso,G. et al.
    Origin: Oasisbr
    The objective of the present study was to identify the single photon emission computed tomography (SPECT) and magnetic resonance (MR) findings in juvenile systemic lupus erythematosus (JSLE) patients with CNS involvement and to try to correlate them with neurological clinical history data and neurological clinical examination. Nineteen patients with JSLE (16 girls and 3 boys, mean age at onset 9.2 years) were submitted to neurological examination, electroencephalography, cerebrospinal fluid analysis, SPECT and MR. All the evaluations were made separately within a period of 15 days. SPECT and MR findings were analyzed independently by two radiologists. Electroencephalography and cerebrospinal fluid analysis revealed no relevant alterations. Ten of 19 patients (53%) presented neurological abnormalities including present or past neurological clinical history (8/19, 42%), abnormal neurological clinical examination (5/19, 26%), and abnormal SPECT or MR (8/19, 42% and 3/19, 16%, respectively). The most common changes in SPECT were cerebral hypoperfusion and heterogeneous distribution of blood flow. The most common abnormalities in MR were leukomalacia and diffuse alterations of white matter. There was a correlation between SPECT and MR (P<0.05). We conclude that SPECT and MR are complementary and useful exams in the evaluation of neurological involvement of lupus.
    2002 article Brazil open access
  6. 6

    The missing Rheic Ocean magmatic arcs: Provenance analysis of Late Paleozoic

    Publication
    by Pereira, M.F.
    Other Authors: Chichorro, M.; Johnston, S.T.; Gutierrez-Alonso, G.; Silva, J.B.; Linnemann, U. et al.
    Early Carboniferous turbiditic sedimentary rocks in synorogenic basins located on both sides of the Rheic suture in SW Iberiawere studied for provenance analysis. An enigmatic feature of this suture, which resulted from closure of the Rheic Ocean with the amalgamation of Pangea in the Late Carboniferous, is that there are no recognizable mid- to Late Devonian subduction-related magmatic rocks,which should have been generated during the process of subduction, on either side of it. U–Pb LA–ICP-MS geochronology of detrital zircons from Early Carboniferous turbidites in the vicinity of the Rheic suture in SW Iberia, where it separates the Ossa–Morena Zone (with Gondwana continental basement) to the north from the South Portuguese Zone (with unknown/Meguma? continental basement) to the south, reveals the abundance of mid- to Late Devonian (51–81%) and Early Carboniferous (13–25%) ages. The Cabrela andMértola turbidites of the Ossa–Morena and South Portuguese zones, respectively, are largely devoid of older zircons, differing from the age spectra of detrital zircons in the oldest (Late Devonian) strata in the underlying South Portuguese Zone, which contain abundant Cambrian and Neoproterozoic ages. Mid- to Late Devonian zircons in the Cabrela Formation (age cluster at c. 391 Ma, Eifelian–Givetian transition) and Mértola Formation (age clusters at c. 369 Ma and at c. 387 Ma, Famennian and Givetian respectively) are attributable to a source terrane made up of magmatic rocks with a simple geological history lacking both multiple tectonic events and older continental basement. The terrane capa- ble of sourcing sediments dispersed on both sides of the suture is interpreted to have been completely re- moved by erosion in SW Iberia. Given that closure of the Rheic Ocean required subduction of its oceanic lithosphere and the absence of significant arc magmatism on either side of the Rheic suture, we suggest: 1) the source of the zircons in the SW Iberia basins was a short-lived Rheic ocean magmatic arc, and 2) given the lack of older zircons in the SW Iberia basins, this short-lived arc was probably developed in an intra-oceanic environment.
    2012 article Portugal open access
  7. 7

    Sedimentary record of the amalgamation and break-up of Pangea: U-Pb detrital zircon geochronology and provenance of Carboniferous-Triassic siliciclastic rocks, SW Iberia

    Publication
    by Pereira, M. F.
    Other Authors: Chichorro, M.; Gutiérrez-Alonso, G.; Gama, C.; Drost, K.; Ribeiro, C. et al.
    In SW Iberia there is a basal unconformity where Triassic sandstones overlie previously deformed Carboniferous turbidites. This important stratigraphic boundary records the transition from the final stages of Pangaea’s amalgamation to the initial stages of break-up. U-Pb dating of detrital zircon from Carboniferous greywackes of the South Portuguese Zone and Triassic sandstones of the Algarve and Alentejo basins was carried out to conduct a study of sedimentary provenance. The radiometric ages obtained by LA-ICP-MS show that most of the samples have common age spectra which are typical of North Gondwana sources: Archean and Paleoproterozoic ages characteristic of the West African craton, Neoproterozoic ages associated with Cadomian and Pan-African orogenies, and Cambrian ages related to the intra-continental rifting of North Gondwana. The only exception is a Visean immature greywacke that was probably derived from Devonian magmatic arcs related to the Variscan orogeny. Very rare pre-Devonian zircons indicate faint contributions from recycled sediments. In contrast the Serpukhovian to Moscovian greywackes are derived from felsic mature source rocks and include Proterozoic and Paleozoic detrital zircons suggesting recycling of an old basement. They also include Ordovician and Silurian detrital zircons, the ages of which have no correspondence in North Gondwana, and thus indicate an external source (Laurussia?). U-Pb ages younger than Ordovician are significant in the Triassic sandstone of the Alentejo basin and resemble the zircon populations of the Serpukhovian to Moscovian greywackes from the South Portuguese Zone. U-Pb ages younger than Neoproterozoic are poorly represented in the zircon population of the Triassic sandstone from the Algarve basin, which rests unconformably upon Moscovian turbidites, pointing to Upper Devonian quartzites of the South Portuguese Zone as probable sources, since they are dominated by Precambrian detrital zircons. These differences occurring in the Triassic basins suggest that detrital zircon populations could be derived from two independent sources and paleo-drainage systems due to complex crustal-block extension architecture.
    2016 lecture Portugal open access
  8. 8

    The Significance of Changes of Source Areas During Carboniferous Turbiditic Deposition (Southwestern Iberia)

    Publication
    by Pereira, Manuel Francisco
    Other Authors: Chichorro, Martim; Gutierrez-Alonso, G.; Vilallonga, Filipa; Drost, K.; Ribeiro, Carlos et al.
    U–Pb dating of detrital zircons from the Carboniferous turbidites of southwestern Iberia (the Cabrela, Mértola, Mira, and Brejeira formations) shows that synorogenic sedimentation during the Carboniferous was marked by significant variations in the source areas, involving the denudation of different crustal blocks and a break in synorogenic volcanism. The Visean is characterized by the accumulation of immature turbidites (the Cabrela and Mértola formations and the base of the Mira Formation). These turbidites were probably formed in relation to sources (magmatic arcs) of Mid–Late Devonian age poorly influenced by sedimentary recycling, as indicated by the near-absence of pre-Devonian zircons, ages that are typical of the Gondwana basement. The presence of Carboniferous grains in Visean turbidites indicates that volcanism was active at this time. Later, Serpukhovian to Moscovian turbiditic sedimentation (the Mira and Brejeira formations) included sedimentary detritus derived from mature felsic source rocks situated far from active magmatism. The abundance of Proterozoic and Palaeozoic zircons reveals strong recycling of the pre-Carboniferous basement. A peri-Gondwanan provenance is indicated by zircon populations with Neoproterozoic (the Cadomian–Avalonian and Pan-African zircon-forming events), Palaeoproterozoic, and Archean (the West African Craton zircon-forming events) ages. The presence of Late Ordovician and Silurian detrital zircons in the Brejeira turbidites, which do not correspond to the Gondwana basement of southwestern Iberia, indicates an external source (Laurussia?).
    2015 lecture Portugal open access
  9. 9

    Variscan Metamorphism

    Publication
    by Ribeiro, M. L.
    Other Authors: Reche, J.; López-Carmona, A.; Aguilar, C.; Bento dos Santos, T.; Chichorro, M. et al.
    Various segments of Variscan crust are currently exposed in Iberia in response to successive tectonic events during the Variscan orogeny itself and subsequent extensional and compressive events during the Alpine cycle, all accompanied by surface erosion, and collectively contributing to their exhumation. We review the main characteristics and geodynamic contexts of the metamorphic complexes developed in Iberia during the Variscan cycle, which include: (i) LP-HT complexes associated to the Cambrian-Early Ordovician rift stage; (ii) HP-LT complexes associated to subduction; and (iii) syn-to-post-collisional, MP and LP/HT complexes from the hinterland to the foreland fold-and thrust belts. All the above contexts are illustrated with case studies. Finally, a review of Variscan metamorphism in the Pyrenees and Catalan Coastal Ranges, located far away from the Rheic suture is also presented.
    2020 book part Portugal open access
  10. 10

    Variscan Metamorphism

    Publication
    by Ribeiro, M.L.
    Other Authors: Reche, J.; López-Carmona, A.; Aguilar, C.; Bento dos Santos, T.; Chichorro, M. et al.
    Various segments of Variscan crust are currently exposed in Iberia in response to successive tectonic events during the Variscan orogeny itself and subsequent extensional and compressive events during the Alpine cycle, all accompanied by surface erosion, and collectively contributing to their exhumation. We review the main characteristics and geodynamic contexts of the metamorphic complexes developed in Iberia during the Variscan cycle, which include: (i) LP-HT complexes associated to the Cambrian-Early Ordovician rift stage; (ii) HP-LT complexes associated to subduction; and (iii) syn-to-post-collisional, MP and LP/HT complexes from the hinterland to the foreland fold-and thrust belts. All the above contexts are illustrated with case studies. Finally, a review of Variscan metamorphism in the Pyrenees and Catalan Coastal Ranges, located far away from the Rheic suture is also presented.
    2019 book part Portugal restricted access